Housing hundreds of centrifuges buried deep underground, much of the Fordow plant is shrouded in mystery. Now President Donald Trump says it's "gone".

Iran has been digging tunnels beneath the Pickaxe mountain, which is just a few minutes from the Natanz nuclear facility. The facility under the peak, also known as Kūh-e Kolang Gaz Lā, is believed to be at a depth of 100 metres.

Joint Chiefs of Staff Chairman Dan Caine said highly classified planning began in 2009 after the discovery of an Iranian construction project inside a mountain